feat: add multi level merge for sorting #15608
There are no files selected for viewing
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,244 @@ | ||
| // Licensed to the Apache Software Foundation (ASF) under one | ||
| // or more contributor license agreements. See the NOTICE file | ||
| // distributed with this work for additional information | ||
| // regarding copyright ownership. The ASF licenses this file | ||
| // to you under the Apache License, Version 2.0 (the | ||
| // "License"); you may not use this file except in compliance | ||
| // with the License. You may obtain a copy of the License at | ||
| // | ||
| // http://www.apache.org/licenses/LICENSE-2.0 | ||
| // | ||
| // Unless required by applicable law or agreed to in writing, | ||
| // software distributed under the License is distributed on an | ||
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY | ||
| // KIND, either express or implied. See the License for the | ||
| // specific language governing permissions and limitations | ||
| // under the License. | ||
|
|
||
| //! Merge that deals with an arbitrary size of spilled files. | ||
| //! This is an order-preserving merge. | ||
|
|
||
| use crate::metrics::BaselineMetrics; | ||
| use crate::{EmptyRecordBatchStream, SpillManager}; | ||
| use arrow::array::RecordBatch; | ||
| use arrow::datatypes::SchemaRef; | ||
| use datafusion_common::{internal_err, Result}; | ||
| use datafusion_execution::memory_pool::MemoryReservation; | ||
| use std::mem; | ||
| use std::ops::Deref; | ||
| use std::pin::Pin; | ||
| use std::sync::Arc; | ||
| use std::task::{Context, Poll}; | ||
|
|
||
| use crate::sorts::streaming_merge::StreamingMergeBuilder; | ||
| use crate::spill::in_progress_spill_file::InProgressSpillFile; | ||
| use crate::stream::RecordBatchStreamAdapter; | ||
| use datafusion_execution::disk_manager::RefCountedTempFile; | ||
| use datafusion_execution::{RecordBatchStream, SendableRecordBatchStream}; | ||
| use datafusion_physical_expr_common::sort_expr::LexOrdering; | ||
| use futures::{Stream, StreamExt}; | ||
|
|
||
| enum State { | ||
| /// Had an error | ||
| Aborted, | ||
|
|
||
| /// Stream did not start yet or between passes | ||
| Uninitialized, | ||
|
|
||
| /// In progress of merging multiple sorted streams | ||
| MultiLevel { | ||
| stream: SendableRecordBatchStream, | ||
| in_progress_file: InProgressSpillFile, | ||
| }, | ||
|
|
||
| /// This is the last level of the merge, just pass through the stream | ||
| Passthrough(SendableRecordBatchStream), | ||
| } | ||
|
|
||
| pub struct MultiLevelSortPreservingMergeStream { | ||
| schema: SchemaRef, | ||
| spill_manager: SpillManager, | ||
| sorted_spill_files: Vec<RefCountedTempFile>, | ||
| sorted_streams: Vec<SendableRecordBatchStream>, | ||
| expr: Arc<LexOrdering>, | ||
| metrics: BaselineMetrics, | ||
| batch_size: usize, | ||
| reservation: MemoryReservation, | ||
| fetch: Option<usize>, | ||
| enable_round_robin_tie_breaker: bool, | ||
|
|
||
| /// The number of blocking threads to use for merging sorted streams | ||
| max_blocking_threads: usize, | ||
|
|
||
| /// The current state of the stream | ||
| state: State, | ||
| } | ||
|
|
||
| impl MultiLevelSortPreservingMergeStream { | ||
| #[allow(clippy::too_many_arguments)] | ||
| pub fn new( | ||
| spill_manager: SpillManager, | ||
| schema: SchemaRef, | ||
| sorted_spill_files: Vec<RefCountedTempFile>, | ||
| sorted_streams: Vec<SendableRecordBatchStream>, | ||
| expr: LexOrdering, | ||
| metrics: BaselineMetrics, | ||
| batch_size: usize, | ||
| reservation: MemoryReservation, | ||
|
|
||
| max_blocking_threads: Option<usize>, | ||
|
|
||
| fetch: Option<usize>, | ||
| enable_round_robin_tie_breaker: bool, | ||
| ) -> Result<Self> { | ||
| // TODO - add a check to see the actual number of available blocking threads | ||
| let max_blocking_threads = max_blocking_threads.unwrap_or(128); | ||
|
|
||
| if max_blocking_threads <= 1 { | ||
| return internal_err!("max_blocking_threads must be greater than 1"); | ||
| } | ||
|
|
||
| Ok(Self { | ||
| spill_manager, | ||
| schema, | ||
| sorted_spill_files, | ||
| sorted_streams, | ||
| expr: Arc::new(expr), | ||
| metrics, | ||
| batch_size, | ||
| reservation, | ||
| fetch, | ||
| state: State::Uninitialized, | ||
| enable_round_robin_tie_breaker, | ||
| max_blocking_threads, | ||
| }) | ||
| } | ||
|
|
||
| fn created_sorted_stream(&mut self) -> Result<SendableRecordBatchStream> { | ||
| let mut sorted_streams = mem::take(&mut self.sorted_streams); | ||
|
|
||
| match (self.sorted_spill_files.len(), sorted_streams.len()) { | ||
| // No data so empty batch | ||
| (0, 0) => Ok(Box::pin(EmptyRecordBatchStream::new(Arc::clone( | ||
| &self.schema, | ||
| )))), | ||
|
|
||
| // Only in-memory stream | ||
| (0, 1) => Ok(sorted_streams.into_iter().next().unwrap()), | ||
|
|
||
| // Only single sorted spill file so stream it | ||
| (1, 0) => self | ||
| .spill_manager | ||
| .read_spill_as_stream(self.sorted_spill_files.drain(..).next().unwrap()), | ||
|
Comment on lines
+126
to
+132
There was a problem hiding this comment. Need to add metrics in these cases |
||
|
|
||
| // Need to merge multiple streams | ||
| (_, _) => { | ||
| let sorted_spill_files_to_read = | ||
| self.sorted_spill_files.len().min(self.max_blocking_threads); | ||
|
|
||
| for spill in self.sorted_spill_files.drain(..sorted_spill_files_to_read) { | ||
| let stream = self.spill_manager.read_spill_as_stream(spill)?; | ||
| sorted_streams.push(Box::pin(RecordBatchStreamAdapter::new( | ||
| Arc::clone(&self.schema), | ||
| stream, | ||
| ))); | ||
| } | ||
|
|
||
| StreamingMergeBuilder::new() | ||
| .with_schema(Arc::clone(&self.schema)) | ||
| .with_expressions(self.expr.deref()) | ||
| .with_batch_size(self.batch_size) | ||
| .with_fetch(self.fetch) | ||
| .with_metrics(if self.sorted_spill_files.is_empty() { | ||
| // Only add the metrics to the last run | ||
| self.metrics.clone() | ||
| } else { | ||
| self.metrics.intermediate() | ||
| }) | ||
| .with_round_robin_tie_breaker(self.enable_round_robin_tie_breaker) | ||
| .with_streams(sorted_streams) | ||
| .with_reservation(self.reservation.new_empty()) | ||
| .build() | ||
| } | ||
| } | ||
| } | ||
|
|
||
| fn poll_next_inner( | ||
| &mut self, | ||
| cx: &mut Context<'_>, | ||
| ) -> Poll<Option<Result<RecordBatch>>> { | ||
| loop { | ||
| match &mut self.state { | ||
| State::Aborted => return Poll::Ready(None), | ||
| State::Uninitialized => { | ||
| let stream = self.created_sorted_stream()?; | ||
|
|
||
| if self.sorted_spill_files.is_empty() { | ||
| self.state = State::Passthrough(stream); | ||
| } else { | ||
| let in_progress_file = | ||
| self.spill_manager.create_in_progress_file("spill")?; | ||
|
|
||
| self.state = State::MultiLevel { | ||
| stream, | ||
| in_progress_file, | ||
| }; | ||
| } | ||
| } | ||
| State::MultiLevel { | ||
| stream, | ||
| in_progress_file, | ||
| } => { | ||
| 'write_sorted_run: loop { | ||
| match futures::ready!(stream.poll_next_unpin(cx)) { | ||
| // This stream is finished. | ||
| None => { | ||
| // finish the file and add it to the sorted spill files | ||
| if let Some(sorted_spill_file) = | ||
| in_progress_file.finish()? | ||
| { | ||
| self.sorted_spill_files.push(sorted_spill_file); | ||
| } | ||
|
|
||
| // Reset the state to create a stream from the current sorted spill files | ||
| self.state = State::Uninitialized; | ||
|
|
||
| break 'write_sorted_run; | ||
| } | ||
| Some(Err(e)) => { | ||
| self.state = State::Aborted; | ||
|
|
||
| // Abort | ||
| return Poll::Ready(Some(Err(e))); | ||
| } | ||
| Some(Ok(batch)) => { | ||
| // Got a batch, write it to file | ||
| in_progress_file.append_batch(&batch)?; | ||
| } | ||
| } | ||
| } | ||
| } | ||
|
|
||
| // Last | ||
| State::Passthrough(s) => return s.poll_next_unpin(cx), | ||
| } | ||
| } | ||
| } | ||
| } | ||
|
|
||
| impl Stream for MultiLevelSortPreservingMergeStream { | ||
| type Item = Result<RecordBatch>; | ||
|
|
||
| fn poll_next( | ||
| mut self: Pin<&mut Self>, | ||
| cx: &mut Context<'_>, | ||
| ) -> Poll<Option<Self::Item>> { | ||
| self.poll_next_inner(cx) | ||
| } | ||
| } | ||
|
|
||
| impl RecordBatchStream for MultiLevelSortPreservingMergeStream { | ||
| fn schema(&self) -> SchemaRef { | ||
| Arc::clone(&self.schema) | ||
| } | ||
| } | ||
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Currently
tokiodon't expose the value of maximum number of blocking threads, and you have no way to know if you reached the limit asspawn_blockingdoesn't return an indication that the current pool is full.